OK I put the hole 500lbs of clay in and the leak was at least slowed or stopped. The heavy rains came and the pond is flowing out the out pipe again. I ordered 250 more pounds to use now that it is full to be sure it isnt leaking higher on the bank.It took a good 2 weeks before I could tell if the leak was better. It is still to early to claim victory but I would say it was worth every penny to try.The clay I used was in the form of sand or sugar and I think this was best for broadcasting.